CN116583461A

CN116583461A - Bag making machine and bag making method

Info

Publication number: CN116583461A
Application number: CN202180081297.7A
Authority: CN
Inventors: 熊本裕司
Original assignee: Totani Corp
Current assignee: Totani Corp
Priority date: 2021-01-18
Filing date: 2021-10-07
Publication date: 2023-08-11
Also published as: US20240017514A1; EP4279404A1; JP7180932B1; JPWO2022153623A1; EP4279404A4; WO2022153623A1

Abstract

The bag making machine comprises: intermittent conveying means for intermittently conveying the body member; an adjustment device for detecting upper and lower thresholds of the length of the body member included in a section from the first drive roller pair to the second drive roller pair; and a moving device for integrally moving the processing device and the sensor as a movable group in the longitudinal direction of the body member. The moving means moves the movable group upstream in response to the adjusting means detecting the upper threshold value and moves the movable group downstream in response to the adjusting means detecting the lower threshold value. When the movable group is moved, the intermittent conveyance device determines an intermittent conveyance distance based on not only the output from the sensor but also the movement distance of the movable group, and conveys the body member by the first driving roller pair.

Description

Bag making machine and bag making method

Technical Field

The present application relates to a bag making machine and a bag making method for sequentially making bags using at least two sheet-like body members.

Background

Such a bag making machine and a bag making method are disclosed in, for example, patent documents 1 to 3. At least two of the sheet-like body members are intermittently transported. The sheet-like body member is processed every time it is intermittently conveyed. For example, the body member is heat sealed in its width direction by the transverse sealing means and cross-cut in its width direction by the cross-cutting means. The bag is formed each time it is cross cut.

Body members with patterns repeatedly printed at print pitches are sometimes used. In the production of bags with printed patterns, it is important that the main body member (its printed pattern) be aligned with high accuracy with respect to the processing devices such as the transverse sealing device and the cross cutting device when intermittent conveyance is temporarily stopped. When the body member is processed (e.g., heat sealed, cross cut) at a location offset from the design, the quality or aesthetics of the bag may be degraded.

When the body member is subjected to various processes such as heat sealing, the printing pitch may be changed due to local and temporal expansion and contraction depending on environmental conditions such as temperature, which may affect the accuracy of alignment. The printing pitch of the printed pattern may also vary due to the quality of the body member used, which also affects the accuracy of the alignment.

In patent document 1, a sensor for detecting a mark of a body member and a pair of driving rollers for intermittently conveying the body member are provided for processing devices such as a transverse heat sealing device and a cross cutting device. The driving roller pair is controlled based on the output of the sensor, and the body member is positioned relative to the sensor and the processing device corresponding to the driving roller pair. In this way, the body member is accurately aligned with respect to each machining device.

According to such intermittent conveyance control, when the intermittent conveyance amount of the body member is different between the pair of driving rollers and the next pair of driving rollers located downstream thereof, the tension of the body member may vary between the pairs of driving rollers, and the tension may exceed an allowable upper limit or lower limit. This may cause a problem that the bag making cannot be continued. In patent document 1, a dancer roll (dancer roll) is provided between these driving roller pairs, and a body member is temporarily stored by the dancer roll, so that this problem is solved. Various methods of tension management are being studied.

The raw material of the bag such as the body member and gusset member is typically a laminate film having high rigidity and durability. Instead, from an environmental point of view, a single raw material (single material), or a composite raw material further comprising a paper base material and a resin layer applied thereto has been attracting attention as a raw material for a bag.

The single raw material is, for example, polyethylene, polypropylene, or the like. The single raw material has high stretchability compared to the laminate film. Therefore, the single material is easily aligned by tension, and on the other hand, when the tension of the body member exceeds the allowable range, a mechanism for coping with this is required.

The composite raw material of the paper base material is low in stretchability. Therefore, it is difficult to align such composite raw materials by tension control. In the case where there is unevenness in the printing pitch of the body member, it is difficult to control the alignment for coping with the unevenness.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2008-100466

Patent document 2: japanese patent application laid-open No. 2012-206458

Patent document 3: japanese patent laid-open No. 2010-105186

Patent document 4: japanese patent laid-open publication No. 2019-196238

Patent document 5: japanese patent laid-open No. 2015-221538

Disclosure of Invention

The present application aims to provide a novel form which combines the alignment of a body member with respect to a processing apparatus and the management of the tension of the body member.

According to one embodiment of the present application, a bag making machine is provided wherein at least two sheet-like body members are cross-cut in a width direction of the body members, bags are sequentially manufactured from the body members, at least any one of the body members comprises repeatedly printed indicia,

the bag making machine includes:

an intermittent conveyance device that intermittently conveys the body members in a state of overlapping each other in a longitudinal direction of the body members;

At least one first processing device for processing the body member each time intermittent conveyance is temporarily stopped;

at least one second processing device for processing the body member each time intermittent conveyance is temporarily stopped; and

an adjusting device provided downstream of the first processing device and upstream of the second processing device,

the intermittent conveyance device includes:

a first sensor provided upstream of the adjustment device for detecting the mark;

a first driving roller pair disposed upstream of the adjustment device and configured to convey the body member in a longitudinal direction of the body member;

a second sensor provided downstream of the adjustment device for detecting the mark; and

a second driving roller pair disposed downstream of the adjusting device for conveying the body member in a longitudinal direction of the body member,

controlling the first pair of drive rollers based on the output from the first sensor, aligning the body member relative to the first processing device when temporarily stopped,

controlling the second pair of drive rollers based on the output from the second sensor, aligning the body member relative to the second processing device when temporarily stopped,

The adjusting device is configured to detect an upper threshold value and a lower threshold value of the length of the body member included in a section from the first driving roller pair to the second driving roller pair,

the bag making machine further comprises:

moving means for integrally moving the first processing means and the first sensor as a movable group in the longitudinal direction of the body member,

the moving means moves the movable group upstream in response to the adjusting means detecting the upper threshold value, and moves the movable group downstream in response to the adjusting means detecting the lower threshold value,

when the movable group is moved, the intermittent conveyance device determines an intermittent conveyance distance based on not only the output from the first sensor but also the movement distance of the movable group, and conveys the body member by the first driving roller pair by the determined intermittent conveyance distance.

The first processing device may include:

a transverse sealing device for heat-sealing the body member in the width direction of the body member every time intermittent conveyance is temporarily stopped; and

and a cooling device for cooling the heat-sealed portion by the transverse sealing device every time the intermittent conveyance is temporarily stopped.

The second processing device may comprise:

and a cross cutting device for cross-cutting the body member in the width direction of the body member every time intermittent conveyance is temporarily stopped.

The second processing device may further comprise: at least one punching device for punching the body member every time the intermittent conveyance is temporarily stopped.

The at least one blanking device may comprise

At least any one of a cut forming device for forming a cut of the bag, or a corner cutting device for forming a corner cut portion of the bag.

The adjustment device may include:

two guide rollers disposed at intervals in the longitudinal direction of the body member and engaged with the body member;

a control roller disposed between the two guide rollers and engaged with the body member;

a biasing member for biasing the control roller toward the body member; and

and a position sensor for detecting the position of the control roller corresponding to the upper threshold value and the lower threshold value.

In addition, according to another embodiment, there is provided a bag-making method comprising cross-cutting at least two sheet-like body members in a width direction of the body members, sequentially making bags from the body members, at least any one of the body members including repeatedly printed marks,

The bag making method comprises the following steps:

intermittently conveying the body members in a state of overlapping each other along a longitudinal direction of the body members by using a first driving roller pair and a second driving roller pair provided downstream of the first driving roller pair;

detecting the length of the body member included in the section using an adjustment device provided in the section from the first drive roller pair to the second drive roller pair;

processing the body member using at least one first processing device disposed upstream of the adjustment device each time intermittent conveyance is temporarily stopped; and

processing the body member using at least one second processing device provided further downstream than the adjusting device every time intermittent conveyance is temporarily stopped,

intermittent conveyance of the body member includes:

detecting the mark using a first sensor disposed further upstream than the adjustment device;

controlling the first pair of drive rollers based on the output of the first sensor to align the body member with respect to the first processing device when temporarily stopped;

detecting the mark using a second sensor disposed further downstream than the adjustment device; and

Controlling the second driving roller pair based on the output of the second sensor to align the body member with respect to the second processing device when temporarily stopped,

in response to the length reaching a prescribed upper threshold, moving the first machining device and the first sensor integrally upstream as a movable group using a moving device,

in response to the length reaching a prescribed lower threshold, integrally moving the movable group downstream using the moving means,

when the movable group is moved, an intermittent conveyance distance is determined based on not only the output from the first sensor but also the movement distance of the movable group, and the determined intermittent conveyance distance is conveyed to the body member by the pair of first driving rollers.

The body member may be a film comprising a single raw material.

The first processing device may include:

a cooling device for cooling the heat-sealed portion by the transverse sealing device every time the intermittent conveyance is temporarily stopped,

The second processing device may comprise:

Drawings

Fig. 1A is a schematic plan view of an upstream portion of an exemplary bag machine, and fig. 1B is a front view thereof.

Fig. 2A is a schematic plan view of a downstream portion of an exemplary bag machine, and fig. 2B is a front view thereof.

Fig. 3A is a schematic view of an exemplary body member after machining, and fig. 3B is a partially enlarged view of a two-dot chain line region of fig. 3A after cross cutting.

Fig. 4 shows an exemplary marking repeatedly printed on the body member.

Fig. 5A to 5C show a schematic view of the adjustment device.

Fig. 6 shows the relationship of tension and applied force.

Detailed Description

Hereinafter, embodiments of the present application will be described with reference to the drawings.

Fig. 1A and 1B schematically illustrate an upstream portion of an exemplary bag machine. The large-sized web 1 is continuously wound from the blank 1' at a constant speed by the pair of driving rollers 21 and is cut along its length direction by the accumulator 20, thereby forming two web-shaped body members 10, 11. The body members 10 and 11 are conveyed in a state of being vertically opposed to each other. The conveying direction of the body members 10, 11 is indicated by a symbol X1. Body members 10, 11 are, for example, plastic films.

Body member 10 and body member 11 may be laminated films including a base material layer and a sealant layer, or films of a single raw material (single material) such as Polyethylene (PE), polypropylene (PP), or the like. The laminated film is strong and has a low elongation. The polyester and polyethylene single raw materials are easy to recycle, environment-friendly, low in melting point and high in expansion ratio. Instead of the film, the body member 10, 11 may include a paper base material and a resin layer applied to the paper base material.

Body members 10, 11 then pass through slack adjuster 22. The tension adjusting device 22 appropriately changes the conveyance of the body member 10, 11 from continuous conveyance to intermittent conveyance. Therefore, the body members 10 and 11 are intermittently conveyed by the intermittent conveyor 4 (fig. 2A and 2B) described later in a section downstream of the slack adjuster 22. That is, the body members 10 and 11 are conveyed, temporarily stopped, and conveyed again. The conveyance and the temporary stop are alternately repeated.

The component supply device 23 (fig. 1B) is provided further downstream than the slack adjuster device 22. The component supply device 23 guides the accessory component 12 (fig. 1A) by a suitable guide member and supplies the component to the space between the body members 10 and 11. The accessory 12 is, for example, a continuous zipper. Hereinafter, an embodiment will be described with the accessory 12 as a slide fastener.

The body members 10, 11 are guided to the guide roller 24 so as to overlap each other at the position of the guide roller 24. Then, the body members 10 and 11 are intermittently conveyed in a state of being overlapped with each other by the intermittent conveyance device 4. When the body members 10, 11 overlap each other, the slide fastener 12 is sandwiched between the body members 10, 11.

The slide fastener sealing device 25 is disposed further downstream than the guide roller 24. The slide fastener sealing device 25 heat-seals the male material and the female material of the slide fastener 12 to the body member 10 and the body member 11 by heat-sealing means or the like every time intermittent feeding is temporarily stopped.

Fig. 2A and 2B schematically illustrate a downstream portion of an exemplary bag machine. The bag making machine includes an intermittent conveyor 4. The intermittent conveyance device 4 intermittently conveys the sheet-like body members 10 and 11 along the longitudinal direction of the body members 10 and 11. The intermittent conveyance device 4 will be described in detail later.

The bag machine further comprises a longitudinal sealing device 30. The longitudinal sealing device 30 heat-seals the body members 10, 11 in the longitudinal direction of the body members 10, 11 by heat-sealing members or the like every time the intermittent conveyance is temporarily stopped. The longitudinal seal is positioned distally relative to the slide fastener 12 (not shown in fig. 2 and A, B) of the body member 10 and 11. Thereby, the longitudinal seal portion 13 is formed (fig. 3A).

The bag machine further comprises a transverse sealing device 32 arranged further downstream than the longitudinal sealing device 30. The transverse sealing means 32 are provided in a plurality, for example two. The lateral sealing device 32 heat-seals the body members 10, 11 in the width direction of the body members 10, 11 by a heat sealing rod or the like every time the intermittent conveyance is temporarily stopped. Thereby, the lateral seal portion 14 is formed (fig. 3A).

The bag machine further comprises spot sealing means 31. The spot sealing device 31 is provided with a plurality of, for example, three. Two spot seals 31 are provided upstream of the lateral seal 32, and one spot seal 31 is provided downstream of the lateral seal 32. The spot sealing device 31 locally heats and pressurizes the slide fastener 12 by a heat sealing member or the like to collapse each time the intermittent conveyance is temporarily stopped. Such a spot sealing device 31 is disclosed in patent document 4, for example. The location of the spot seal is the location for forming the transverse seal portion 14.

The bag machine further comprises a cooling device 33 arranged further downstream than the transverse sealing device 32 and the spot sealing device 31. The cooling device 33 is provided in plural, for example, two. The cooling device 33 cools the portion (i.e., the transverse sealing portion 14) heat-sealed by the transverse sealing device 32 by a cooling member or the like every time the intermittent conveyance is temporarily stopped.

The bag machine further includes a blanking device 34 and a blanking device 35 disposed downstream of the cooling device 33. As the punching device, for example, a notch forming device 34 and a corner cutting device 35 are used. The notch forming apparatus 34 forms the notch hole 15 by punching the body member 10 and the body member 11 with a punch blade or the like every time the intermittent conveyance is temporarily stopped (fig. 3A). The blanking position of which is within the transverse sealing portion 14.

The corner cutting device 35 forms the corner cutting portion 16 by punching the body member 10, 11 with a punch blade, thomson blade, or the like every time intermittent feeding is temporarily stopped (fig. 3A). The blanking positions of which are the both ends of the transverse sealing portion 14.

The bag machine further comprises a cross cutting device 36 arranged further downstream than the blanking device 34, 35. The cross cutting device 36 cuts the body member 10, the body member 11, and the slide fastener 12 by a cutter or the like in the width direction of the body member 10, the body member 11 every time the intermittent conveyance is temporarily stopped. The cross cut position thereof is the position of the transverse sealing portion 14. At each time of cross cutting, the pouch is formed of a portion cut off at the time of cross cutting.

Thus, the longitudinal sealing portion 13 is positioned along one end edge of the bag. The transverse sealing portions 14 are positioned along both sides of the bag. The slide fastener 12 provides free opening and closing of the bag. The crushed portions of the slide fastener 12 are located on both sides of the bag (the lateral seal portions 14), thereby providing the bag with sealability (see patent document 4 and the like). The hole 15 for incision is divided into two parts by cross cutting, and becomes an incision 150 for unsealing the bag (see fig. 3B). The corner cut portions 16 are located at the four corners of the bag, thereby imparting security to the bag. The seal portions 13 and 14 remain as marks in the bag, and thus may become an element even if the aesthetic appearance of the bag is affected.

Although not shown, the body members 10 and 11 are repeatedly printed with a pattern at a printing pitch along the longitudinal direction thereof, to manufacture a pouch with a printed pattern. As shown in fig. 4, indicia M are included in each printed pattern of body member 10 and/or body member 11. That is, the mark M is repeatedly printed on at least one of the body member 10 and the body member 11 at a printing pitch. The mark M may be part of a printed motif. The marks M may be contrast change points included in each printed pattern as disclosed in WO2020/026620, for example.

The intermittent conveyance device 4 includes a first sensor 40, a second sensor 41, a first drive roller pair 42, a second drive roller pair 43, and a control unit 44 for intermittently conveying the body members 10, 11 at a print pitch.

The first sensor 40 is disposed downstream of the lateral seal device 32 and upstream of the cooling device 33 for detecting the mark M. An optical sensor is used as the first sensor 40.

The first sensor 40 detects the mark M on the body member 10 when intermittently conveyed and stopped at the reference position. At this time, when the mark M passes through the reference position and stops, the passing distance (passing distance) is measured. When the mark M is not detected, that is, when the mark M does not reach the reference position, the first sensor 40 moves upstream until the mark M is detected, measures the amount of movement, and returns to the reference position.

On the body member, the dimension between the mark M and the line to be cross-cut (hereinafter, cross-cut line) is predetermined. The first sensor 40 is positioned such that, in the adjustment device 5 described later, the mark M is located in the detection area (reference position) of the first sensor 40 when the cross cutting position of the cross cutting device 36 exactly coincides with the cross cutting line in a state where the control roller 51 is located at the center position of the movable area thereof.

The dimensions between the mark M and the portion to be sealed laterally (hereinafter, the lateral sealing portion) are also predetermined on the body member. The spot sealing device 31, the lateral sealing device 32, and the cooling device 33 are positioned such that their processing positions (spot sealing position, lateral sealing position, cooling position) coincide with the lateral sealing position when the first sensor 40 detects the mark M (at the reference position).

The first driving roller pair 42 is disposed downstream of the cooling device 33 and upstream of the punching devices 34 and 35. The first driving roller pair 42 intermittently rotates by a driving source such as a servo motor (not shown), and thereby intermittently conveys the body member 10 and the body member 11 sandwiched therebetween.

The second sensor 41 is disposed downstream of the first driving roller pair 42, more specifically, the punching device 34 and the punching device 35 and upstream of the cross cutting device 36 for detecting the mark M. An optical sensor is used as the second sensor 41, and the operation thereof is the same as that of the first sensor 40. The second sensor 41 is positioned such that the mark M is located in the detection area (reference position) of the second sensor 41 when the cross cutting position of the cross cutting device 36 coincides exactly with the cross cutting line.

The size between the mark M and the part to be punched (hereinafter, punching part) is also predetermined on the body member. The punching devices 34 and 35 are positioned so that the punching positions thereof coincide with the punching portions when the marks M are detected by the second sensor 41 (when the marks M are located at the reference positions).

The control unit 44 includes, for example, a controller, a motor driver, and the like. The two sensors 40, 41 and the two drive roller pairs 42, 43 are electrically connected to the control unit 44.

The control unit 44 receives the output signal from the first sensor 40, and controls the first drive roller pair 42, specifically, the conveyance speed (distance) of the body member 10 or 11 by the first drive roller pair 42, via the motor based on the output. Thus, even if the printing pitch varies or varies for some reason, the body member 10 and the body member 11 are intermittently conveyed at the actual printing pitch at the position of the first sensor 40. More specifically, when it is determined that the conveyance of body member 10, 11 is advanced from the design value at the position of first sensor 40, control unit 44 decreases the conveyance distance by first drive roller pair 42 by the advanced distance measured by first sensor 40. On the other hand, when it is determined that the conveyance of the body member 10, 11 is delayed from the design value at the position of the first sensor 40, the control unit 44 increases the conveyance distance by the first driving roller pair 42 by the delay distance measured by the first sensor 40.

The control unit 44 performs control using the mark M, the first sensor 40, and the first driving roller pair 42, and when temporarily stopping the body member 10 and the body member 11, positions the body member 10 and the body member 11 (the lateral seal portions thereof) with respect to the spot sealing device 31 (the spot sealing positions thereof), the lateral sealing device 32 (the lateral seal positions thereof), and the cooling device 33 (the cooling positions thereof).

The control unit 44 receives the output signal from the second sensor 41, and controls the second driving roller pair 43, specifically, the conveying speed of the body member 10 or 11 by the second driving roller pair 43, via the motor based on the output. Accordingly, even if the printing pitch varies or varies for some reason, the body member 10 and the body member 11 are intermittently conveyed at the actual printing pitch at the position of the second sensor 41. More specifically, when it is determined that the conveyance of the body member 10, 11 is advanced from the design value at the position of the second sensor 41, the control unit 44 reduces the conveyance distance by the second driving roller pair 43 by the advanced distance measured by the second sensor 41. On the other hand, when it is determined that the conveyance of the body member 10, 11 is delayed from the design value at the position of the second sensor 41, the control unit 44 increases the conveyance distance by the second driving roller pair 43 by the delay distance measured by the second sensor 41.

The control unit 44 performs control using the mark M, the second sensor 41, and the second driving roller pair 42, and when temporarily stopping the body member 10 and the body member 11, positions the body member 10 and the body member 11 (the intersecting line of the body member) with respect to the intersecting-cutting device (the intersecting-cutting position of the intersecting line of the body member). At the same time, by the control, the body member 10 and the body member 11 (the punching portions thereof) are also aligned with respect to the punching device 34 and the punching device 35 (the punching positions thereof).

For example, the positions of the spot sealing device 31, the lateral sealing device 32, and the cooling device 33 when the mark M is detected by the first sensor 40 (when the mark M is located at the reference position) determine the design position as a default value. In the case where body members 10 and 11 are made of a single material having a large expansion and contraction ratio, the positions may be slightly deviated due to temperature and humidity conditions or the like. In this case, the operator can visually adjust the machining positions (spot sealing position, lateral sealing position, cooling position) thereof.

In the embodiment, the body member 10, the body member 11 (printed pattern) are aligned with respect to the spot sealing device 31 (spot sealing position), the lateral sealing device 32 (lateral sealing position) and the cooling device 33 (cooling position) by the set of the first sensor 40 and the first driving roller pair 42. Hereinafter, these devices 31 to 33 will be referred to as first processing devices.

The body members 10 and 11 (the printed pattern thereof) are aligned with respect to the cross cutting device 36 (cross cutting position), the punching device 34, and the punching device 35 (punching position) by the set of the second sensor 41 and the second driving roller pair 43. These devices 34-36 will be referred to hereinafter as second processing devices.

Since the first sensor 40 is located in the vicinity of the first processing device, the printed pattern can be aligned with high accuracy with respect to the processing position of each first processing device. Further, since the second sensor 41 is located in the vicinity of the second processing device, the printed pattern can be aligned with high accuracy with respect to the processing position of each second processing device. Therefore, the printed pattern can be aligned with high accuracy with respect to the two processing positions of the first processing device and the second processing device. Therefore, even if the print pitch varies depending on environmental conditions such as heat generated in the heat sealing process or the quality of the body members 10 and 11, the bag making machine of the embodiment can produce a beautiful printed bag.

In the intermittent conveyance control, for example, when the conveyance distance of the body member 10 or the body member 11 at the reference position of the first sensor 40 tends to be delayed and the conveyance distance of the body member 10 or the body member 11 at the reference position of the second sensor 41 tends to be advanced and the conveyance distance of the body member 10 or the body member 11 at the reference position of the second sensor 41 decreases, the body member 10 or the body member 11 may be loosened in a section from the first drive roller pair 42 to the second drive roller pair 43. In particular, in the case where the body member 10 and the body member 11 are made of a single material, this is likely to occur.

In contrast, when the conveyance distance of the body member 10 or the body member 11 at the reference position of the first sensor 40 tends to be advanced to decrease the conveyance distance by the first driving roller pair 42, and the conveyance distance of the body member 10 or the body member 11 at the reference position of the second sensor 41 tends to be delayed to increase the conveyance distance by the second driving roller 43, the body member 10 or the body member 11 may exceed the allowable range in the section.

Further, there are cases where the tension of the body member 10 and the body member 11 differs depending on the pair of driving rollers, and tension management in the section becomes important. Thus, the bag machine includes the following structure.

The bag machine includes an adjustment device 5 (fig. 2), and the adjustment device 5 is provided downstream of the first sensor 40 and the first driving roller pair 42 and upstream of the second sensor 41 and the second driving roller pair 43, and adjusts the tension. As for the adjusting device 5, details thereof are shown in fig. 5A. The adjusting device 5 includes: two guide rollers 50, which are disposed at intervals in the longitudinal direction of the body members 10, 11 and are not displaced, engage with the body members 10, 11; and a control roller 51 provided between the guide rollers 50 and engaged with the body member 10 and the body member 11. Although not shown, the adjustment device 5 further includes a biasing member that supports the control roller 51, is capable of being displaced in the up-down direction, and biases the body 10 and the body 11 downward with a constant biasing force.

As shown in fig. 6, the following expression is substantially established when the winding angle of the body member 10, 11 to the control roller 51 is 2θ, the applied force including the weight of the control roller 51 is F, the tension of the body member 10, 11 is T, and the minute force such as the frictional force in the roller rotation direction is ignored.

F＝2Tsinθ

Therefore, by controlling the force F to be small when the position of the control roller 51 is high (θ is small) and controlling the force F to be large when the position of the control roller 51 is low (θ is large), the tension of the body member 10, 11 can be maintained within a substantially constant range.

By controlling the urging force of the urging member in this manner, the tension of the body member 10 and the body member 11 in the section between the pair of driving rollers 42 and 43 can be controlled.

The adjustment device 5 is further configured to detect an upper threshold value and a lower threshold value of the lengths of the body member 10 and the body member 11 (hereinafter, simply referred to as "body member section length") included in the section from the first drive roller pair 42 to the second drive roller pair 43. Although not shown, the adjustment device 5 further includes a position sensor for detecting the position of the control roller 51 corresponding to these threshold values.

For example, when the body member section length is shorter, the control roller 51 is located further upward (fig. 5B), and when the body member section length is longer, the control roller 51 is located further downward (fig. 5C). Thus, the body member section length corresponds to the position of the control roller 51 in the up-down direction. Therefore, the adjustment device 5 detects that the body element section length reaches the lower threshold value/the upper threshold value by detecting that the control roller 51 is located at the upper limit position (see the broken line in fig. 5B)/the lower limit position (see the broken line in fig. 5C) by the position sensor.

The bag machine further comprises a moving device 6 (fig. 2), wherein the moving device 6 is configured to move the first processing device 31, the first processing device 32, the first processing device 33, and the first sensor 40 as a movable group by a small distance in the longitudinal direction of the body member 10, the body member 11, that is, upstream and downstream with respect to other devices of the bag machine.

The moving device 6 includes a frame on which a movable group is mounted, a rack-and-pinion mechanism for moving the frame, and a drive source such as a motor for operating the rack-and-pinion mechanism, although details thereof are omitted. Instead, the moving device 6 may have a known structure such as a structure in which a rail is disposed and driven by a worm wheel. The moving device 6 operates as follows based on the output of the position sensor of the adjusting device 5.

When the adjustment device 5 detects that the body member section length reaches the lower threshold, that is, the control roller 51 is positioned at the upper limit position by the intermittent conveyance control by the control unit 44, the movement device 6 moves the movable group downstream by a small distance in response to this, and further, the intermittent conveyance distance by the first driving roller pair 42 is changed in accordance with this, whereby the control roller 51 is lowered.

For example, a case where the intermittent conveyance pitch as a reference is set on a scale of 100mm and the movement amount of the movable group is set on a scale of 2mm will be described in more detail.

When the adjustment device 5 detects that the control roller 51 is located at the upper limit position at the time of stopping the conveyance of the body member 10 and the body member 11, the intermittent conveyance device 4 and the movement device 6 operate as follows.

The intermittent conveyance device 4 detects the mark M by the first sensor 40, and calculates a conveyance delay of 0.5mm based on the output thereof. After the detection, sealing process, and cooling by the first sensor 40, the moving device 6 moves the movable group 2mm downstream.

The intermittent conveyance device 4 determines the next intermittent conveyance distance by the first driving roller 42 to be 102.5mm (100mm+0.5mm+2mm) based on the output result obtained by the first sensor 40 and the moving distance of the movable group. The intermittent conveyance device 4 conveys the body members 10 and 11 by 102.5mm (determined intermittent conveyance distance) by the first driving roller pair 42 in the next intermittent conveyance cycle. Here, +0.5mm is a correction amount determined by the output of the first sensor 40, and +2mm is a correction amount determined based on the movement of the movable group, and is equal to the movement distance of the movable group.

By performing the above control, when the position of the first sensor 40 is taken into consideration, the positions of the spot sealing device 31, the lateral sealing device 32, and the cooling device 33 with respect to the mark M can be accurately determined by conveying the body members 10, 11 by 100.5 mm. Further, by additionally conveying the body member 10, 11 to the downstream side of the movable group by the first driving roller pair 42 by the movement amount (2 mm), the body member section length is not lower than the lower threshold value.

On the other hand, when the adjustment device 5 detects that the body member segment length reaches the upper threshold, that is, the control roller 51 is located at the lower limit position by the intermittent conveyance control by the control unit 44, the moving device 6 moves the movable group upstream by a small distance in response to this, and further, changes the intermittent conveyance distance by the first driving roller pair 42, thereby raising the control roller 51.

When the adjustment device 5 detects that the control roller 51 is positioned at the lower limit position at the time of stopping the conveyance of the body member 10 and the body member 11, the intermittent conveyance device 4 and the movement device 6 operate as follows.

The intermittent conveyance device 4 detects the mark M by the first sensor 40, and calculates, for example, that the conveyance delay is 0.5mm based on the output thereof. After the detection, sealing process, and cooling by the first sensor 40, the moving device 6 moves the movable group 2mm upstream.

The intermittent conveyance device 4 determines the next intermittent conveyance distance by the first driving roller 42 to be 98.5mm (100mm+0.5 mm-2 mm) based on the output result obtained by the first sensor 40 and the moving distance of the movable group. The intermittent conveyance device 4 conveys the body members 10 and 11 by 98.5mm (determined intermittent conveyance distance) by the first driving roller pair 42 in the next intermittent conveyance cycle. Here, +0.5mm is a correction amount determined by the output of the first sensor 40, -2mm is a correction amount determined based on the movement of the movable group, and is equal to the movement distance of the movable group.

As a result, the positions of the spot sealing device 31, the lateral sealing device 32, and the cooling device 33 with respect to the mark M can be accurately determined. Further, by conveying body members 10, 11 by a small amount of movement (2 mm) toward the upstream side of the movable group by first drive roller pair 42, the section length of body members 10, 11 does not exceed the upper threshold.

As described above, when the movable group is moved, the movement distance is considered as the correction amount for the intermittent conveyance distance by the first driving roller pair 42. Therefore, the body element section length is controlled to an appropriate value without exceeding the range from the lower threshold value to the upper threshold value, and the tension of the body element 10 and the body element 11 can be controlled within a certain range.

The mechanical movable range of the control roller 51 is wider than the upper limit position and the lower limit position, and the force applied to the control roller 51 can be appropriately set depending on the material of the body member, the width, and the like.

The bag machine continuously calculates the distance from the cross cutting position to the reference position of the first sensor 40 by continuously measuring the moving distance of the movable group. That is, the bag making machine can continuously estimate the reference position of the first sensor 40, and the reference position of the first sensor 40 varies according to the conditions of the body member 10 and the body member 11 that expand and contract even when the environment changes due to temperature, humidity, or the like.

The moving distance and the moving timing of the movable group can be appropriately set. For example, the movable group may be moved by a 3mm scale or a 5mm scale, and when the range of variation in the body member interval length of the body members 10, 11 is large, the movable group may be moved by 2 or 3 scale.

With the above configuration, not only can the high-precision alignment be performed for each group of processing apparatuses controlled by one sensor, but also the tension in the section from the drive roller pair to the next drive roller pair can be appropriately managed. Therefore, even when the bag is made of the printed packaging material with high expansion and contraction rate, stable bag making can be realized.

In particular, since the films constituting the body members 10 and 11 are very easily stretched by the heat generated in the heat sealing step, the intermittent conveyance control according to the embodiment after the heat sealing step is extremely effective.

In addition, in the case of adding a processing device requiring high-precision alignment in addition to the respective devices 31 to 36 of the embodiment, the intermittent conveyance control and tension management as described above may be performed by arranging an additional set of a sensor and a pair of driving rollers in the vicinity of the processing device and providing a moving device that integrally moves the sensor, the pair of driving rollers, and the processing device in the upstream-downstream direction. Thus, the body members 10, 11 can be aligned to the machining position of the machining device with high accuracy and the tension can be properly managed.

In general, in order for an operator to visually confirm the lateral seal position or the spot seal position, a certain degree of space is ensured between the lateral seal device 32/the spot seal device 31 and the cooling device 33. The first sensor 40 and its movable unit are disposed effectively using the empty space of the bag making machine.

The two sheet-like body members 10 and 11 may be formed by folding the web 1 in half along the longitudinal direction thereof without cutting the web. In this case, the two sheet-like body members 10, 11 are connected to each other via a bending line. In the case of such a bag, the longitudinal sealing means 30 are omitted.

The component supply device 23 may supply other accessory members such as gussets (bottom gussets, roof gussets, side gussets) to the body member 10, 11 in addition to the slide fastener 12, and/or may supply other accessory members such as gussets (bottom gussets, roof gussets, side gussets) to the body member 10, 11 instead of the slide fastener 12. In addition, in addition to the body members 10, 11, gussets may be formed from the web 1. The longitudinal seal 30, the transverse seal 32, and the like may also be heat-sealed in a state in which the gusset member is interposed between the body members 10, 11. It will be readily understood by those skilled in the art that the intermittent conveyance control can be applied to various bag making processes other than the embodiment.

Films of a single raw material are easier to stretch, lower in melting point, and more difficult to manage in terms of sealing temperature and transport speed than laminated films. In addition, the quality of the film of a single material varies widely. Thus, the single raw material film is more difficult to align in the bag than the laminate film. In the embodiment, as described above, the body members 10 and 11 can be aligned with high accuracy even when they are elongated, and thus, the present invention is particularly effective for bag making using a film of a single material. In the flexible packaging industry, the bag making of films using a single raw material is being reevaluated from a recycling standpoint, and thus the bag making of embodiments is very effective.

The film of the single raw material is substantially lower than the melting point of the laminated film. Therefore, when a single raw material film is used, the upstream two-point sealing device 31 can be heated at a temperature lower than the heating temperature at the time of laminating the films, and damage to the body member 10, 11 can be suppressed. Further, the flattened portion is further pressurized and heated by the two lateral sealing devices 32, so that the thickness of the flattened portion of the slide fastener 12 can be further reduced while suppressing damage to the body members 10, 11. Further, the most downstream one of the spot sealing apparatuses 31 may further pressurize the flattened portion softened by heating and pressurizing. Thus, a leak-free seal can be reliably achieved.

In the case where a film of a single material is used as the body members 10, 11, the adjusting device 5 can be omitted from the bag making machine by utilizing its high stretchability. The alignment is performed by the first sensor 40 at the position of the first drive roller pair 42 and by the second sensor 42 at the position of the second drive roller pair 43. Therefore, the number of pitches of the body members 10, 11 included in the section from the first drive roller pair 42 to the second drive roller pair 43 is not changed. Therefore, a certain degree of tension may be applied to the body members 10 and 11 in the initial state. Even if body members 10 and 11 are expanded and contracted, the number of pitches in the interval is not changed, and the punching positions of punching devices 34 and 35 are not deviated from those of body members 10 and 11.

That is, if the actual printing pitch is shorter than the initial printing pitch due to the non-uniformity or shrinkage of the body members 10, 11, the body members 10, 11 are stretched in the section and the tension is increased, but the printing position is not deviated from the punching position. In contrast, if the actual printing pitch is longer than the initial printing pitch due to the non-uniformity or the elongation of the body members 10, 11, the tension applied to the body members 10, 11 in the section is relaxed to a value lower than the initial state, and the printing position does not deviate from the punching position.

In consideration of the physical properties of the body members 10, 11, the tension in the initial state is determined so that the tension can be canceled by tension adjustment even when the body members 10, 11 are expanded or contracted. This can be handled by the movement of the movable group, provided that body member 10, body member 11 is excessively extended and relaxed, or excessively contracted and excessively strained.

In this way, when the tension fluctuation width of the body member 10 and the body member 11 is increased to perform alignment, the alignment accuracy with respect to uneven printing becomes high, while the variation in tension at the time of sealing becomes large. As a result, the quality of the sealing process tends to be unstable.

On the other hand, when the tension fluctuation range is reduced by using the adjusting device 5, the variation in tension at the time of sealing becomes small. As a result, the quality of the sealing process is stable. However, when there is unevenness in printing, there is a limit in the adjustment range under tension. In this case, the adjustment can be performed by the movement of the movable group.

The body member of the paper substrate is less stretchable than the body member of the resin substrate. Therefore, when there is unevenness in the printing pitch of the body member of the paper base material, it is difficult to cope with this by tension control. In the case of the bag making machine illustrated in the drawings, the positions of the spot sealing device 31, the lateral sealing device 32, and the cooling device 33 with respect to the mark M can be accurately determined by the movement of the movable group without depending on tension control.

Description of symbols

10. 11: body member

32: transverse sealing device (first processing device)

33: cooling device (first processing device)

34. 35: blanking device (second processing device)

36: cross cutting device (second processing device)

4: intermittent conveying device

40: first sensor

41: second sensor

42: first driving roller pair

43: second driving roller pair

5: adjusting device

50: guide roller

51: control roller

6: mobile device

M: marking

Claims

1. A bag making machine, characterized in that at least two sheet-like body members are cut crosswise in the width direction of the body members, bags are sequentially produced from the body members, at least any one of the body members contains repeatedly printed marks,

the bag making machine includes:

the intermittent conveyance device includes:

the bag making machine further comprises:

2. The bag machine of claim 1, wherein the bag machine further comprises a bag machine,

the first processing device includes:

3. The bag machine according to claim 1 or 2, wherein,

the second processing device includes:

4. The bag machine according to claim 3, wherein,

the second processing device further comprises: at least one punching device for punching the body member every time the intermittent conveyance is temporarily stopped.

5. The bag machine of claim 4, wherein the bag machine further comprises a bag machine,

the at least one blanking device comprises:

6. The bag machine according to any one of claims 1 to 5, wherein,

The adjusting device includes:

a biasing member for biasing the control roller toward the body member; and

7. A method for producing bags, characterized in that at least two sheet-like body members are cut crosswise in the width direction of the body members, bags are produced in sequence from the body members, at least any one of the body members contains repeatedly printed marks,

the bag making method comprises the following steps:

processing the body member each time intermittent conveyance is temporarily stopped using at least one first processing device provided upstream of the adjustment device; and

Processing the body member each time intermittent conveyance is temporarily stopped by at least one second processing device provided downstream of the adjustment device,

intermittent conveyance of the body member includes:

8. The method for producing bags according to claim 7, wherein,

the body member is a film comprising a single raw material.

9. A method for producing bags according to claim 7 or 8, wherein,

the first processing device includes:

the second processing device includes: